• Title/Summary/Keyword: spin-structure

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Calculation of the Magnetic Moments for Transition Metal Complexes (I). The Magnetic Moments for Distorted Octahedral $[Ti(III)A_3B_3]$ Type Complexes [A and B = Cl, O, N, Br] (전이원소착물의 자기모멘트의 계산 (제1보). 일그러진 팔면체 $[Ti(III)A_3B_3]$형태 착물의 자기모멘트 [A 및 B = Cl, O, N, Br])

  • Sangwoon Ahn;Eu Suh Park;Byung Bin Park
    • Journal of the Korean Chemical Society
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    • v.24 no.2
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    • pp.91-100
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    • 1980
  • A formula for calculation of the magnetic moments for octahedral $[Ti(III)A_3B_3]$ type complexes with axial symmetry has been developed and the magnetic moments for these complexes are calculated, using the experimental values of the distortion parameters$({\delta})$, spin-orbit coupling constants and orbital reduction factors. The calculated magnetic moments for axially distorted octahedral $[Ti(III)A_3B_3]$ type complexes are in resonable agreement with the experimental valuest It is found that the calculated magnetic moments decrease as the extent of axial distortion increases and the orbital reduction factor decreases. A calculation method of the magnetic moments for octahedral $[Ti(III)A_3B_3]$ type complexes which are in a ligand field of lower than axial symmetry has also been developed and the structure of distorted octahedral $[Ti(III)A_3B_3]$ type complexes are discussed on the basis of the of the calculated magnetic moments.

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Magnetism during adsorption of oxygen in Pt segregated $Pt_3Ni$ (111): Density Functional Study

  • Kumar, Sharma Bharat;Kwon, O-Ryong;Odkhuu, Dorj;Hong, Soon-Cheol
    • Proceedings of the Korean Magnestics Society Conference
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    • 2011.12a
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    • pp.14-14
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    • 2011
  • Limited understanding of the surface properties of $Pt_3Ni$ for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cell (PEMFC) has motivated the study of magnetic properties and electronic structures of Pt segregated $Pt_3Ni$ (111) surface during adsorption of oxygen molecule on it. The first principle method based on density functional theory (DFT) is carried out. Nonmagnetic Pt has induced magnetic moment due to strong hybridization between Ni 3d and Pt 5d. It is found that an oxygen molecule prefers bridge site with Pt rich subsurface environment for adsorption on the surface of Pt segregated $Pt_3Ni$ (111). It is seen that there is very small charge transfer from $O_2$ to Pt. The curve of energy versus magnetic moment of the oxygen explains the magnetic moments in transition states. We found the dissociation barrier of 1.07eV significantly higher than dissociation barrier 0.77eV on Pt (111) suggesting that the dissociation is more difficult on Pt segregated $Pt_3Ni$ (111) surface. The spin polarized densities of states are presented in order to understand electronic structures of Pt and $O_2$ during the adsorption in detail.

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The Preparation and Characterization of Bismuth Layered Ferroelectric Thin Films by Sol-Gel Process (II. Dielectric Properties of Ferroelectric $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$ Thin Films Prepared by MOD Process) (솔 - 젤법을 이용한 Bismuth Layered Structure를 가진 강유진성 박막의 제조 및 특성평가에 관한 연구 (II. MOD법으로 제조한 강유전성 $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$ 박막의 유전특성))

  • 최무용;송석표;정병직;김병호
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.12 no.1
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    • pp.62-68
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    • 1999
  • Ferroelectric $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$(x=0, 0.1, 0.2, 0.3) thin films were deposited on $Pt/SiO_2/Si$ substrate by MOD(Metalorganic Decomposition) process. Metal carboxylate and metal alkoxide were used as precursors, and 2-methoxyethanol, xylene as solvents. After spin coating, thin films were pre-annealed at $400^{\circ}C$, followed by RTA(Rapid Thermal Annealing) and final annealing at $800^{\circ}C$ in oxygen atmosphere. These procedures were repeated three times to obtain thin films with the thickness of $2000{\AA}$. To enhance the nucleation and growth of layered-perovskite phase, thin films were rapid-thermally annealed above $720^{\circ}C$ in oxygen atmosphere. As RTA temperature increased, fluorite phase was transformed to layered-perovskite phase. And the change of Nb contents affected dielectric / electrical properties and microstructure. The ferroelectric characteristics of $Sr_{0.7}/B_{2.3}(Ta_{1-x}Nb_x)_2O_9$ thin film were Pr=8.67 $\mu{C}/cm^2$, Ec=62.4kV/cm and $I_{L}=1.4\times10^{-7}A/cm^2$ at the applied voltage of 5V, respectively.

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Effects of Masseter and Cervical Muscle Activity in Temporomandibular Joint Disorder (저작근 및 경부근 긴장도가 측두하악장애에 미치는 영향)

  • Jung, Jae-Young;Kim, Sung-Su
    • Journal of Korean Medicine Rehabilitation
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    • v.20 no.3
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    • pp.37-60
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    • 2010
  • Objectives : The purpose of this study was to investigate the relationship between masseter and cervical muscle activity and temporomandibular disorder in female office workers. Methods : Experimental group of 24 healthy subjects complained of temporomandibular joint related to computer use which lasted more than 3 months in the past year and was present in the past 7 days as well as on the day of test. Control group of 20 healthy subjects had no complaints of minimal discomfort on the day of test, and had no discomfort in the past 7 days. If they had reported discomfort in the past 12 months, it was of a short duration(<3 months) and resolved at least 3 months prior to participation. Outcomes were assessed by meridian-electromyography(MEMG), whole spin x-ray, mandibular function impairment questionnaire(MFIQ), neck disability index(NDI), visual analog scale(VAS), Beck depression inventory(BDI), stress reaction inventory(SRI) and Holmes & Rahe social readjustment rating scale(SRRS). Results : The contraction power of masseter muscle, upper trapezius, sternocleido-mastoid muscle and erector spinae by MEMG was significantly higher in the experimental group. The muscle fatigue of masseter muscle and sternodeido-mastoid muscle by MEMG was significantly higher in the experimental group. SRI was significantly higher in experimental group. There was no significant difference between two groups in the Jackson's angle, Cobb's method and cranio-cervical posture. Conclusions : The results suggest that temporomandibular disorder related mental stress but physical stress does not change cervical structure significantly.

Design of Echo Classifier Based on Neuro-Fuzzy Algorithm Using Meteorological Radar Data (기상레이더를 이용한 뉴로-퍼지 알고리즘 기반 에코 분류기 설계)

  • Oh, Sung-Kwun;Ko, Jun-Hyun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.5
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    • pp.676-682
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    • 2014
  • In this paper, precipitation echo(PRE) and non-precipitaion echo(N-PRE)(including ground echo and clear echo) through weather radar data are identified with the aid of neuro-fuzzy algorithm. The accuracy of the radar information is lowered because meteorological radar data is mixed with the PRE and N-PRE. So this problem is resolved by using RBFNN and judgement module. Structure expression of weather radar data are analyzed in order to classify PRE and N-PRE. Input variables such as Standard deviation of reflectivity(SDZ), Vertical gradient of reflectivity(VGZ), Spin change(SPN), Frequency(FR), cumulation reflectivity during 1 hour(1hDZ), and cumulation reflectivity during 2 hour(2hDZ) are made by using weather radar data and then each characteristic of input variable is analyzed. Input data is built up from the selected input variables among these input variables, which have a critical effect on the classification between PRE and N-PRE. Echo judgment module is developed to do echo classification between PRE and N-PRE by using testing dataset. Polynomial-based radial basis function neural networks(RBFNNs) are used as neuro-fuzzy algorithm, and the proposed neuro-fuzzy echo pattern classifier is designed by combining RBFNN with echo judgement module. Finally, the results of the proposed classifier are compared with both CZ and DZ, as well as QC data, and analyzed from the view point of output performance.

Growth and Optoelectric Characterization of CdGa$_2$Se$_4$ Sing1e Crystal Thin Films (Hot Wall Epitaxy (HWE)에 의한 CdGa$_2$Se$_4$ 단결정 박막 성장과 광전기적 특성)

  • 홍광준;박창선
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.167-170
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    • 2001
  • The stochiometric mix of evaporating materials for the CdGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, CdGa$_2$Se$_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 630$^{\circ}C$ and 420$^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of CdGa$_2$Se$_4$ single crystal thin films measured from Hall erect by van der Pauw method are 8.27x10$\^$17/ cm$\^$-3/, 345 $\textrm{cm}^2$/V$.$s at 293 K, respectively. From the Photocurrent spectrum by illumination of perpendicular light on the c-axis of the CuInSe$_2$ single crystal thin film, we have found that the values of spin orbit splitting ΔSo and the crystal field splitting ΔCr were 106.5 meV and 418.9 meV at 10 K, respectively. From the photoluminescence measurement on CdGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$\_$X/) existing only high quality crystal and neutral bound exiciton (D$\^$0/,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral donor bound excision were 8 meV and 13.7 meV, respectivity. By Haynes rule, an activation energy of impurity was 137 meV,

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Growth and Optoelectric Characterization of $ZnGa_{2}Se_{4}$ Sing1e Crystal Thin Films (Hot Wall Epitaxy (HWE)에 의한$ZnGa_{2}Se_{4}$단결정 박막 성장과 광전기적 특성)

  • 박창선;홍광준
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.163-166
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    • 2001
  • The stochiometric mix of evaporating materials for the ZnGa$_2$Se$_4$ single crystal thin films was prepared from horizontal furnace. To obtain the single crystal thin films, ZnGa$_2$Se$_4$ mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were 61$0^{\circ}C$ and 45$0^{\circ}C$, respectively. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of ZnGa$_2$Se$_4$ single crystal thin films measured from Hall effect by van der Pauw method are 9.63x10$^{17}$ cm$^{-3}$ , 296 $\textrm{cm}^2$/V.s at 293 K, respectively, From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the ZnGa$_2$Se$_4$ single crystal thin film, we have found that the values of spin orbit splitting $\Delta$So and the crystal field splitting $\Delta$Cr were 251.9 MeV and 183.2 meV at 10 K, respectively. From the photoluminescence measurement on ZnGa$_2$Se$_4$ single crystal thin film, we observed free excition (E$_{x}$) existing only high quality crystal and neutral bound excition (A$^{0}$ ,X) having very strong peak intensity. Then, the full-width-at-half-maximum(FWHM) and binding energy of neutral acceptor bound excition were 11 meV and 24.4 meV, respectivity. By Haynes rule, an activation energy of impurity was 122 meV.on energy of impurity was 122 meV.

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The Emotional Sensibility Estimation System for Front-load Washer (드럼세탁기의 감성품질 측정 시스템)

  • Suh, Sang-Won;Lee, Chang-Goo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.3
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    • pp.821-826
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    • 2010
  • The door-lock switch is one of the most important part in the front-load washer. As an safety system, it keeps the door locked while the front-load washer or the dish washer is working and generating heat and spin. The door of front-load washer needs the emotionality as well as the safety because the consumers always get feels when using it. In this paper, We study about emotional factors in the door of front-load washer and analyze the difference of emotionality as the structure of the door-lock switch changed. For this, we analyze the force graph by using the software and the jig which can measure the force while the door is opened or closed.

Effort Analysis of Unit Testing Conducted by Non-Developer of Source Code (원개발자 부재에 따른 원시코드 기반의 단위테스트 노력 분석)

  • Yoon, Hoijin
    • Journal of Information Technology Services
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    • v.11 no.4
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    • pp.251-262
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    • 2012
  • Unit testing is one of the test levels, which tests an individual unit or a group of related units. Recently, in Agile Development or Safety-critical System Development, the unit testing plays an important role for the qualities. According to the definition of unit testing, it is supposed to be done by the developers of units. That is because test models for the unit testing refers to the structure of units, and others but its original developers hardly can understand the structures. However, in practice, unit testing is often asked to be done without the original developers. For example, it is when faults are revealed in customer sites and the development team does not exit any more. In this case, instead of original developers, other developers or test engineers take a product and test it. The unit testing done by a non-developer, who is not the original developer, would cause some difficulties or cause more cost. In this paper, we tests an open source, JTopas, as a non-developer, with building test models, implementing test codes, and executing test cases. To fit this experiment to practical testing situations, we designed it based on the practices of unit testing, which were surveyed through SPIN(Software Process Improvement Network). This paper analyzes which part of unit testing done by non-developers needs more effort compared to the unit testing done by original developers. And it concludes that Agile Development contributes on reducing the extra effort caused by non-developers, since it implements test codes first before developing source code. That means all the units have already included their own tests code when they are released.

Temperature dependence of photocurrent spectra for $AgGaSe_2$ single crystal thin film grown by hot wall epitaxy (Hot Wall Epitaxy(HWE) 법에 의해 성장된 $AgGaSe_2$ 단결정 박막의 광전류 온도 의존성)

  • Hong, Kwang-Joon;Bang, Jin-Ju
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.179-180
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    • 2007
  • Single crystal $AgGaSe_2$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_2$ source at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $AgGaSe_2$ thin films measured with Hall effect by van der Pauw method are $4.05{\times}\;10^{16}/cm^3$, $139\;cm^2/V{\cdot}s$ at 293 K. respectively. The temperature dependence of the energy band gap of the $AgGaSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)=1.9501\;eV\;-\;(8.79{\times}10^{-4}\;eV/K)T^2$/(T + 250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_2$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the phcitocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}So$ definitely exists in the $\Gamma_5$ states of the valence band of the $AgGaSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_1$-, $B_1$-, and $C_1$-exciton peaks for n = 1.

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